1. Pertussis: New Vaccine, New Strategies
March 22, 2005
National Immunization Conference
Washington, D.C.
Karen R. Broder, MD, FAAP
LCDR, United States Public Health Service
Christina M. Mijalski, MPH
National Immunization Program

2. Vaccinating to Prevent Pertussis throughout the Lifecycle
Routine pertussis vaccination:
DTaP at 2 months to 6 years

3. Major Pertussis Vaccination Challenges
Adolescent/Adults:
Immunity wanes ~5-10 years after completing childhood vaccination
Young infants:
- Not protected, incomplete 3-dose DTaP series
- Increased risk of pertussis-related death
- Adults and adolescents can be the source of pertussis

4. Vaccinating to Prevent Pertussis throughout the Lifecycle
Pertussis vaccination
- Accelerated DTaP schedule
- Vaccination (“cocoon”)
close contacts of infants
Additional vaccinations
- Vaccination during
Pregnancy
- Neonatal vaccination
Pertussis vaccination,
acellular pertussis vaccine
- Universal
- Selected populations
Routine pertussis vaccination:
DTaP at 2 months to 6 years

5. Timeline: Childhood Pertussis Vaccination in the United States
1940s: Whole cell pertussis vaccines (DTP) recommended
1992: Advisory Committee on Immunization Practices (ACIP) published recommendations for use of acellular pertussis vaccines (DTaP) for 4th and 5th doses
1997: ACIP published recommendations for use of DTaP for all 5 doses from 2 months to 6 years of age
: Coverage 3+ doses DTP/DTaP: >90%

6. Childhood DTaP Vaccines Licensed in United States, 2005
Vaccines vary by type and quantity of pertussis components:
- Tripedia®, sanofi pasteur
- Infanrix™, Pediarix™, GlaxoSmithKline
DAPTACEL™, sanofi pasteur
Vaccine efficacy for 3 doses DTaP*: 80%-93%
* WHO case definition: 21 days paroxysmal cough, laboratory confirmation or epi-link to a lab-confirmed case

7. Acellular Pertussis Vaccines for Adolescents and Adults, United States
Safe and immunogenic
Licensure status:
- US: Biologics License Applications submitted to US FDA, summer 2004 for two adolescent/adult acellular pertussis vaccines combined with tetanus and diphtheria toxoids (Tdap)**
**Tetanus toxoids, reduced diphtheria toxoid and acellular pertussis vaccine adsorbed (Tdap)

8. Tdap Vaccines Under FDA Review
• GlaxoSmithKline: Boostrix™: indicated years of age
- Pertussis components reduced quantity and similar to Infanrix™ DTaP
- Diphtheria and tetanus similar to Td*
• sanofi pasteur: Adacel™: indicated years of age
- Pertussis reduced quantity and similar to DAPTACEL™ DTaP
*composition of Td manufactured by sanofi pasteur

9. Potential Tdap Vaccination Strategies, United States
ACIP currently developing recommendations for potential Tdap use
First US recommendation will likely focus on adolescents
Substantial pertussis morbidity
Existing infrastructure for vaccination

10. Recommended Adolescent Immunization Schedule ─ United States, January 2005

11. Adolescent Tdap Recommendations Under Consideration
Routine Tdap vaccination at years of age instead of Td (yellow bar)
- Vaccinate at years of age only if adolescent missed the Td dose (green bar)
Same as above − PLUS
- Routine Tdap vaccination for older adolescents who received Td ≥5 years earlier*
*Td and Tdap may need to be spaced by ≥5 years to minimize adverse events

12. National Physicians’ Survey: Perspectives on Potential Adolescent Pertussis Vaccination (Tdap) Recommendations
University of Michigan and CDC
Preliminary Results

13. Recommended Adolescent Immunization Schedule ─ United States, January 2005

14. Adolescent Td Coverage Levels
Data sources
Method
(age-group)
Coverage
National Health Interview Survey, 2002*
Td dose per shot card (13-15 yrs)
33%
Schools: 3 states with Td school laws, 2000 and 2002 (FL†, MO*, KS*)
School immunization records (middle school)
48%-97%
* CDC, unpublished data
† Fogarty et al. Public Health Rep., 2004

15. Question:
Would Physicians Accept the Adolescent Tdap Recommendations under Consideration?
Routine Tdap vaccination at years of age instead of Td (yellow bar)
- Vaccinate at years of age only if adolescent missed the Td dose (green bar)
Same as above − PLUS
- Routine Tdap vaccination for older adolescents who received Td ≥5 years earlier*
*Td and Tdap may likely need to be spaced by ≥5 years to minimize adverse events

16. Methods
Questionnaire: A national, cross-sectional mailed survey administered by the University of Michigan, January 2005
- Fact sheet about pertussis and Tdap included
Population: Pediatricians and family physicians (~300 from each group) randomly selected from the AMA Physician Masterfile
Eligibility: Provide outpatient primary care to ≥1 adolescent patient per week

17. Survey Response 594 surveys mailed 321 responses Final sample (n=297)
298 Pediatricians
296 Family physicians
594 surveys mailed
19 undeliverable 9 Peds/10 FPs
165 Pediatricians (57%)
321 responses
156 Family physicians (55%)
24 not eligible
(no adolescent patients)
11 Pediatricians
13 Family physicians
154 Pediatricians
Final sample (n=297)
143 Family physicians

18. Practice Settings of Eligible Physicians
Proportion of Physicians
Peds
n=154
FPs
n=143
Private, independent office
75%
66%
Practice network/ HMO 7%
19%
Hospital/ medical center 3% 1%
University health system 8%
10%
Public Clinic/ Community Health Center 5%
Peds: Pediatricians
FPs: Family physicians

19. Adolescent Patients 11-18 Years of Age Seen for Outpatient Primary Care by Physician Type
P<.0001 for comparison of PDs vs FPs

20. Reported Practice’s “Routine” Approach to Administering Td to Adolescents*† ‡
* When indicated

21. Reported “Major” Barriers to Adolescent Td Vaccination† ‡ * †

22. Physicians’ Beliefs Agree pertussis is a “serious enough disease” to use Tdap for adolescents, rather than Td
P<.0001

23. Physician Preference: How should adolescent vaccination recommendations “be structured”?

24. Additional Data from Meningococcal Conjugate Vaccine Survey
Comparable sample
(different Peds, FPs)
Comparable response rate
Peds: 59%
FPs: 55%
Comparable volume of adolescent patients
Also administered January 2005

25. Meningococcal Survey Healthcare Practices Proportion of physicians reporting more than half of their adolescent patients have… † † ‡
† P<.001
‡ P<.01 †
Percent of Physicians

26. Conclusion (1)
Physicians will likely accept routine adolescent Tdap vaccination instead of Td (target: years of age)
- Most physicians report routinely administering Td to adolescents during preventive care visits
- Few physicians report they disagree with replacing Td with Tdap for adolescents

27. Conclusion (2)
Routine Tdap vaccination for older adolescents who received Td ≥5 years earlier might pose challenges
- Less than 1/3 of physicians report the majority of adolescent patients years of age have a preventive care visit
- Lack of adolescent patient visits reported as barrier for Td vaccination

28. Conclusion (3)
Adolescent Tdap vaccination practices will likely differ between pediatricians and family physicians
- Peds more commonly report routinely vaccinating adolescents with Td at the year preventive visit than FPs
- FPs more commonly report barriers to Td vaccination than Peds
- Peds and FPs report different beliefs about pertussis

29. Acknowledgements CDC University of Michigan Shannon Stokley
Sarah Clark
Matt Davis
Anne Cowan
CDC
Shannon Stokley
Katrina Kretsinger
Amanda Cohn
Trudy V. Murphy
Barbara Slade
Margaret Cortese
Marty Roper
Tej Tiwari
Daniel Fishbein
Oleg Bilukha
Nancy Rosenstein
John Moran
Gregory Wallace
ACIP Pertussis Working Group
Jon Abramson
Members and Consultants